Parting material for molds



Patented Jan. 15, 1929.

UNITED STATES QHARLES I. STAMM, OF CINCINNATI, OHIO.

PARTING MATERIAL FOR MOLIDS.

No Drawing.

My invention relates to parting materials such as are useful in forming lines of fracture between surfaces of molding compounds used in the component parts of molds.

In the art of molding, metallic or wooden flasks, the component parts .of which are usually termed the cope and the drag, are filled with molding sand or other suitable molding materials and the melted metal is poured into the compound mold formed by placing the cope and drag together. There are, of course, surfaces exposed on both the cope and the drag which meet, and parting or parting compound is used to make a clean line of fracture between these meeting surfaces. Parting is also used to keep molding sand from sticking to metal or wooden parts elsewhere in the molding operation.

It is the object of my invention to provide a new material which may be used for parting purposes, and which may be manufactured much more inexpensively than any parting compound heretofore known or used.

For use as parting, there have been used a number of materials such as white barytes, rotten stone, serpentine, magnesium carcarbonate and calcium carbonate with which mixtures of oils, greases, fats and waxes have been incorporated. The process of incorporating a certain percentage of a lubricant with a powder used has always been a diificult matter and it has added a great deal to the expense involved in preparing the parting.

My invention contemplates the use and discloses the manufacture of a finely pulverized residual oil shale which may occur in nature or which may be recoverd as a biproduct of the distillation of oil shale.

As a definite percentage of oil which may be successfully used and which responds readily to the test for parting, I prefer to use oil shale having about twenty-five to thirty gallons of oil per ton or about ten percent by weight of oil to shale. If it is desired to use an oil shale having a higher oil content, the lighter distillates may be re- Application filed February 26, 1926. Serial No. 90,986.

verized oil shale sifted through a 100 mesh I screen is quite satisfactory.

The test for parting is conducted as follows: A small quantity of the parting is ioured into water and the finger is then inserted through the floating parting into the water. If the finger when removed has an apparently dry layer of parting on it the quantity of oil in it is sufficient. A higher quantity of oil than twenty-five gallons per ton may be used but the increased quantity of oil has no beneficial properties and only adds to the expense of making the parting.

In distilling oil shale it is seldom worth while to carry on the distillation to the point where the high gravity lubricating oil group of hydrocarbons is recovered, so that as raw material for my parting the shale from which the lighter distillates have been recovered provides a very inexpensive base. I may mix recovered oil bearing shale or undistilled oil bearing shale with a certain percentage of other ingredients and thus make an effective parting by grinding and sifting.

lVhile I have in the foregoing specification disclosed a novel product which is preferably made by grinding and sifting it should be understood that the sifting is merely the most practical way of preparing the powder in a finely divided state. It is also possible to separate the fine powder from the coarse by centrifugal separation or air flotation with the production of an equally good product.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. A material for use as parting for moldper ton and said shale mechanically reduced 1 to a finely divided state.

4. The process of making parting for molding use Which consists in treating oil shale to remove surplus oil therefrom, then grinding and reducing the residue to a 15 state of fine pulverization.

CHARLES P. STAMM. 

